This specification relates to data processing evaluating user interfaces.
User interfaces facilitate user interaction with various resources and applications. For example, user interfaces generally include various interactive elements that enable a user to input data (e.g., using text boxes), make data selections (e.g., using radio buttons, check boxes, or drop down menus), navigate to resources (e.g., by interacting with an embedded link), and change visual aspects of the user interface (e.g., resizing the window, scrolling to other portions of a document, or using zoom controls). User satisfaction with a given website or application can depend on the user's experience interacting with the user interface.